System and method for filtering and eliminating noise from natural language utterances to improve speech recognition and parsing

ABSTRACT

The systems and methods described herein may filter and eliminate noise from natural language utterances to improve accuracy associated with speech recognition and parsing capabilities. In particular, the systems and methods described herein may use a microphone array to provide directional signal capture, noise elimination, and cross-talk reduction associated with an input speech signal. Furthermore, a filter arranged between the microphone array and a speech coder may use band shaping, notch filtering, and adaptive echo cancellation to optimize a signal-to-noise ratio associated with the speech signal. The speech signal may then be sent to the speech coder, which may use adaptive lossy audio compression to optimize bandwidth requirements associated with transmitting the speech signal to a main unit that provides the speech recognition, parsing, and other natural language processing capabilities.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. patent application Ser. No. 12/168,554, entitled “Systems and Methods for Responding to Natural Language Speech Utterance,” filed Jul. 7, 2008, which issued as U.S. Pat. No. 7,809,570 on Oct. 5, 2010, and which is a divisional of U.S. patent application Ser. No. 10/452,147, entitled “Systems and Methods for Responding to Natural Language Speech Utterance,” filed Jun. 3, 2003, which issued as U.S. Pat. No. 7,398,209 on Jul. 8, 2008, and which claims the benefit of U.S. Provisional Patent Application Ser. No. 60/384,388, entitled “General Purpose Device for Speech Query and Response,” filed Jun. 3, 2002. The contents of the above cross-referenced U.S. Patents, U.S. Patent Applications, and U.S. Provisional Patent Application are hereby incorporated by reference in their entirety.

FIELD OF THE INVENTION

The present invention relates to the retrieval of online information or processing of commands through a speech interface. More specifically, the invention is a fully integrated environment allowing users to submit natural language speech questions and commands. Information that is sought may be obtained from a wide range of disciplines, making local and network queries to obtain the information, and presenting results in a natural manner even in cases where the question asked or the responses received are incomplete, ambiguous or subjective. The invention may further allow users to control devices and systems either locally or remotely using natural language speech commands.

BACKGROUND OF THE RELATED ART

A machine's ability to communicate with humans in a natural manner remains a difficult problem. Cognitive research on human interaction shows that a person asking a question or giving a command typically relies heavily on context and the domain knowledge of the person answering. On the other hand, machine-based queries (e.g., questions, commands, requests, and/or other types of communications) may be highly structured and are not inherently natural to the human user. Thus, human questions and machine processing of queries may be fundamentally incompatible. Yet the ability to allow a person to make natural language speech-based queries remains a desirable goal.

Much work covering multiple methods has been done in the fields of natural language processing and speech recognition. Speech recognition has steadily improved in accuracy and today is successfully used in a wide range of applications. Natural language processing has previously been applied to the parsing of speech queries. Yet, current systems are generally unable to provide a complete environment for users to make natural language speech queries and receive natural sounding responses. There remains a number of significant barriers to creation of a complete natural language speech-based query and response environment.

SUMMARY OF THE INVENTION

According to an aspect of the invention, one object of the invention is to overcome these and other drawbacks of prior systems.

According to one aspect of the invention, in order for machines (e.g., computer devices) to properly respond to a question and/or a command that is in a natural language form, machine processable queries and commands may be formulated after the natural language question and/or command has been parsed and interpreted.

In another aspect of the invention, systems are provided which may overcome the deficiencies of prior systems through the application of a complete speech-based information query, retrieval, presentation and command environment. This environment makes maximum use of context, prior information, domain knowledge, and user specific profile data to achieve a natural environment for one or more users making queries or commands in multiple domains. Through this integrated approach, a complete speech-based natural language query and response environment may be created. Further, at each step in the process, accommodation may be made for full or partial failure and graceful recovery. The robustness to partial failure is achieved through the use of probabilistic and fuzzy reasoning at several stages of the process. This robustness to partial failure promotes the feeling of a natural response to questions and commands.

According to another aspect of the invention, the system comprises a speech unit interface device that receives spoken natural language queries, commands and/or other utterances from a user, and a computer device or system that receives input from the speech unit and processes the input (e.g., retrieves information responsive to the query, takes action consistent with the command and performs other functions as detailed herein). The system may further generate a natural language speech response in response to the user and/or generate a natural language speech message without any prompting from a user such as an alert message.

According to another aspect of the invention, the speech unit may be incorporated into the computer device or system, or may be a separate structure. If a separate structure, the speech unit may be connected to the computer device via a wired or wireless connection. If a wireless connection, a base unit may be connected to the computer, internally or externally, to communicate with the speech unit.

According to another aspect of the invention, the computer device or system may comprise a stand alone or networked PC, a PDA or other portable computer device, or other computer device or system. For convenience, these and other computer alternatives shall be referred to simply as a computer. One aspect of the invention comprises software that is installed onto the computer, where the software comprises one or more of the following modules: a speech recognition module for capturing the user input; a parser for parsing the input, a text to speech engine module for converting text to speech; a network interface for enabling the computer to interface with one or more networks; a graphical user interface module; and an event manager for managing events. Preferably, the event manager is in communication with a dictionary and phrases module, a user profile module that enables user profiles to be created, modified, and accessed, a personality module that enables various personalities to be created and used, an agent module, an update manager, and one or more databases.

According to another aspect of the invention domain specific behavior and information is organized into agents. Agents are autonomous executables that receive, process and respond to user questions, queries, and commands. The agents provide complete, convenient and re-distributable packages or modules of functionality, typically for a specific domain or application. Agents can be complete packages of executable code, scripts, links to information, and other forms of communication data, required to provide a specific package of functionality, usually in a specific domain. In other words, an agent includes everything that is needed to extend the functionality of the invention to a new domain. Further, agents and their associated data can be updated remotely over a network as new behavior is added or new information becomes available. Agents can use system resources and the services of other, typically more specialized, agents. Agents can be distributed and redistributed in a number of ways including on removable storage media, transfer over networks or attached to emails and other messages. An update manager is used to add new agents to the system or update existing agents.

According to another aspect of the invention, license management capabilities allowing the sale of agents by third parties to one or more users on a one time or subscription basis may be provided. In addition, users with particular expertise may create agents, update existing agents by adding new behaviors and information, and make these agents available for other users.

In order to enhance the natural query and response environment, the system may format results in a manner enhancing the understandability to the user. The optimal formatting and presentation depends on the context of the questions, the contents of the response being presented, the history of the interaction with the user, the user's preferences and interests and the nature of the domain. Information presented in a rigid, highly formatted, or structured manner seems unnatural to most people. Thus a system simulates some aspects of human “personality.” In some cases, the presentation of the response and the terms used are randomized so they do not appear rigidly formatted or mechanical. The use of other simulated personality characteristics is also desirable. For example, a response that may be upsetting to the user is best presented in a sympathetic manner. Finally, the results of many queries are long text strings, lists, tables or other lengthy sets of data. Natural presentation of this type of information presents particular challenges. Simply reading the long response is generally not preferred. Therefore the system parses the most important sections from the response and, at least initially, only reports these. Determining what parts of a long response are presented depends on the context of the questions, the contents of the response being presented, the history of the interaction with the user, the user's preferences and interests and the nature of the domain. At the same time the system gives the user interactive control over what information and how much information is being presented, to stop the response all together, or to take other actions.

According to another aspect of the invention, the system may process and respond to both questions or queries and commands. Keywords or context are used to determine if the user's utterance is a command or query. Some utterances can include both aspects of a command and a query or question. For example, a user may say, “record my favorite TV program.” A query is required to determine the name, the channel, and time for the user's favorite TV program. A command must be executed to set a video recorder to capture this program.

For each user utterance including a question or query or set of questions or queries, the system may perform multiple steps possibly including:

-   -   capture of the user's question or query through accurate speech         recognition operating in a variety of real-world environments;     -   parse and interpret the question or query;     -   determine the domain of expertise required and context, invoking         the proper resources, including agents;     -   formulate one or more queries to one or more local and/or         network data sources or sending appropriate commands to local or         remote devices or the system itself;     -   perform required formatting, variable substitutions and         transformations to modify the queries to a form most likely to         yield desired results from the available sources;     -   execute the multiple queries or commands in an asynchronous         manner and dealing gracefully with failures;     -   extract or scrape the desired information from the one or more         results, which may be returned in any one of a number of         different formats;     -   evaluate and interpret the results, including processing of         errors, gathered and combine them into a single best result         judged to be “best” even if the results are ambiguous,         incomplete, or conflicting;     -   perform required formatting, variable substitutions and         transformations to modify the results to a form most easily         understood by the user; and     -   present the compound result, through a text to speech engine, to         the user in a useful and expected manner.

The above steps preferably are performed while accounting for the domain of expertise required, the context for the question or command, domain specific information, the history of the user's interaction, user preferences, information sources or commands available, and responses obtained from the sources. At each stage probabilistic or fuzzy set decision and matching methods can be applied to deal with inconsistent, ambiguous, conflicting and incomplete information or responses. In addition, the use of asynchronous queries that may result in rapid and graceful failure of some queries or commands may allow the system to robustly return results quickly and in a manner that seems natural to the user.

Many everyday questions are inherently subjective and result in answers that are a matter of option or consensus as much as fact. Such questions are often ad hoc in their nature, as well. The system, according to another aspect of the invention, may use probabilistic and fuzzy set decision and matching methods to first identify the subjective nature of the question and to evaluate a range of possible answers, selecting the one answer or few answers that best represent the type of result desired by the user. The context and expected results from a particular question may be highly dependent on the individual asking the question. Therefore, the system may create, store and use extensive personal profile information for each user. Information in the profile may be added and updated automatically as the user uses the system or may be manually added or updated by the user or by others. Domain specific agents may collect, store and use specific profile information, as may be required for optimal operations. Users can create commands for regularly used reports, automatically generated alerts, and other queries and for the formatting and presentation of results. The system may use profile data in interpreting questions, formulating queries, interpreting results of queries and presenting answers to the user. Examples of information in a user profile includes, history of questions asked, session histories, formatting and presentation preferences, special word spelling, terms of interest, special data sources of interest, age, sex, education, location or address, place of business, type of business, investments, hobbies, sports interests, news interests and other profile data.

To create a natural question and response environment, the system according to one aspect of the invention, may attempt to provide rapid responses without requiring any additional information. The system may determine the mostly likely context or domain for a user's question or command, for example, by using a real-time scoring system or other technique. Based on this determination, the system may invoke the correct agent. The agent makes one or more queries and rapidly returns a formatted response. Thus, a user can receive a direct response to a set of questions, each with a different response or context. In some cases, the available information, including the query results, may not adequately answer the question. In such a situation, the user may be asked one or more questions to resolve the ambiguity. Additional queries may then be made before an adequate response is made. In these cases, the system may use context information, user profile information and domain specific information to minimize the interaction with the user required to deliver a response.

If the confidence level of the domain or context score is not high enough to ensure a reliable response, the system can request that the user verify the question or command is correctly understood. In general, the question may be phrased to indicate the context of the question including all criteria or parameters. If the user confirms that the question is correct the system may proceed to produce a response. Otherwise, either the user can rephrase the original question, perhaps adding additional information to remove ambiguity, or the system may ask one or more questions to attempt to resolve the ambiguity or other actions may taken.

Although the system, according to another aspect of the invention, is intended to be able to accept most any natural language question or command, ambiguity can still be a problem. To assist users formulate concise questions and commands the system may support a voice query language. The language may help users clearly specify the keywords or contexts of the question or command along with the parameters or criteria. The system may provide built in training capabilities to help the user learn the best methods to formulate their questions and commands.

In order to make the responses to user's questions and commands seem more natural, the system may employ one or more dynamically invokable personalities. Personalities have specific characteristics, which simulate the behavioral characteristics of real humans. Examples of these characteristics include sympathy, irritation, and helpfulness. The personality also randomizes aspects of responses, just as a real human would do. This behavior includes randomization of terms used and the order of presentation of information. Characteristics of the personality are invoked using probabilistic or fuzzy set decision and matching methods, and using criteria including the context for the question, the history of the user's interaction, user preferences, information sources available, and responses obtained from the sources.

According to another aspect of the invention, special procedures to present information that is in the form of long text strings, tables, lists or other long response sets may be employed. Simply presenting a long set of information in an ordered manner is not natural nor what most users have in mind. The system, using for example, probabilistic or fuzzy set matching methods, may extract the most relevant information to the user and presents these subsets first. Further the system may provide commands allowing the user to skip through the list, find keywords or key information in the list or stop processing the list altogether.

In addition to the ability to process user questions and commands, the invention may provide local or remote control functions for the system or for other devices. Users may initiate commands locally or remotely. Several techniques for executing remote operations are possible, for example, the use of a telephone or other audio connection. Other remote command techniques may be used. The processing of these commands is performed in a nearly identical manner to a question. One difference being that the result of the command is generally an action rather than a response. Examples of control operations supported by the invention include, finding and playing music, film, games or other entertainment media, control of the appliances or other electronic or electro-mechanical devices, security systems control, audio, text and video conferencing (including Voice over IP conferencing), operating integrated messaging environments and other control operations. By using an optional analog or digital telephone interface or a data network interface, the invention can provide remote control capability of the computer or and auxiliary devices connected to the computer. For example, if the computer is connected via an interface to one or more auxiliary devices, a remote user can use this capability to remotely control or program the operation of the auxiliary device. For example, this enables recording of a television program, checking the status of a home security system, checking voice mail messages, hearing and responding to email messages, and much more. For each user command utterance the system may execute a number of steps possibly including:

-   -   capture the user's command through accurate speech recognition         operating in a variety of real-world environments;     -   parse and interpret the command;     -   determine the domain for the command and context, invoking the         proper resources, including agents;     -   formulate device specific commands for the system or external         devices;     -   route command to system, or external devices, including external         devices connected to data networks;     -   receive and process results of command, including errors; and     -   optionally, provide response to user indicating the success or         failure of the command, and possibly including state         information.

The system may be used in conjunction with a wide range of platform environments. These environments include, as a peripheral to a PC, a portable or wearable computer or other computer, embedded in a PC or other computer, on a personal digital assistant (e.g., a PDA with wireless networking capability, in a specialized device such as a bar code scanner or payment terminal, on a wireless telephone, or other platforms). If the invention is used with a mobile or portable device that has position location capability, the location data can be used by the invention as part of the context for user questions. A user may use the system on one or more devices. In this case history and profile information for the user may be synchronized between the multiple devices on a periodic basis or other basis.

According to another aspect of the invention, the system may be deployed in a network of devices using common base of agents, data, information, user profiles and histories. Each user can then interact with, and receive the same services and applications at any location equipped with the required device on the network. For example, multiple devices on which the invention is deployed, and connected to a network, can be placed at different locations throughout a home, place of business or other location. In such a case, the system may use the location of the particular device addressed by the user as part of the context for the questions asked.

Multiple users may use the system at different times or during interleaved or overlapping sessions. The system recognizes the user either by name or voice. Once the user is recognized, the system invokes the correct profile. If multiple users are addressing the system in overlapping or interleaved sessions, the system determines which user is stating each question or command and applies the correct profile and context. For applications requiring security, the user is verified, typically by using voiceprint matching or requesting a password or pass-phrase from the user. When multiple users are engaged in interleaved sessions, the system gracefully resolves conflicts using a probabilistic or fuzzy set decision method. This process simulates the manner in which a human would address multiple questions. For example, the system may answer short questions first at times, while answering questions in the order received at other times.

Given the desire for domain specific behavior, user specific behavior and domain specific information, the system, according to another aspect of the invention, may allow both users and content providers to extend the system capabilities, add data to local data sources, and add references to network data sources. To allow coverage of the widest possible range of topics, the system allows third party content developers to develop, distribute and sell specialized or domain specific system programs and information. Content is created though creation of new agents, scripting existing agents, adding new data to agents or databases and adding or modifying links to information sources. Distribution of this information is sensitive to the users' interests and use history and to their willingness to pay or not.

According to another aspect of the invention, the system may allow users to disseminate their knowledge without programming. The system may include mechanisms that allow users to post and distribute agents and information in their particular areas of expertise, to improve system capability. Further, users can extend the system and configure it to their own preferences, add information to their profile to define new questions or queries, extend and modify existing questions and queries, add new data sources, update data sources, set preferences and specify presentation parameters for results.

Since the invention may operate in many environments, including environments with background noise, point noise sources and people holding conversations, filtering of speech input may be performed. The invention may use, for example, either one-dimensional or two-dimensional array microphones to receive human speech. The array microphones can use fixed or dynamic beam forming techniques. The array pattern may be adjusted to maximize gain in the direction of the user and to null point noise sources. Speech received at the microphones may then be processed with analog or digital filters to optimize the bandwidth, cancel echoes, and notch-out narrow band noise sources. Following filtering, the system may use variable rate sampling to maximize the fidelity of the encoded speech, while minimizing required bandwidth. This procedure may be particularly useful in cases where the encoded speech is transmitted over a wireless network or link.

Some example applications for the invention include, but are not limited to, the following:

-   -   white pages and yellow pages lookups to find email addresses,         telephone numbers, street addresses and other information for         businesses and individuals;     -   personal address book, calendars and reminders for each user;     -   automatic telephone dialing, reading and sending emails and         pages by voice and other communications control functions;     -   map, location and direction applications;     -   movie or other entertainment locator, review information and         ticket purchasing;     -   television, radio or other home entertainment schedule, review         information and device control from a local or remote user;     -   weather information for the local area or other locations;     -   stock and other investment information including, prices,         company reports, profiles, company information, business news         stories, company reports, analysis, price alerts, news alerts,         portfolio reports, portfolio plans, etc.;     -   flight or other scheduled transportation information and         ticketing;     -   reservations for hotels, rental cars and other travel services;     -   local, national and international news information including         headlines of interest by subject or location, story summaries,         full stories, audio and video retrieval and play for stories;     -   sports scores, news stories, schedules, alerts, statistics, back         ground and history information, etc.;     -   ability to subscribe interactively to multimedia information         channels, including sports, news, business, different types of         music and entertainment, applying user specific preferences for         extracting and presenting information;     -   rights management for information or content used or published;     -   horoscopes, daily jokes and comics, crossword puzzle retrieval         and display and related entertainment or diversions;     -   recipes, meal planning, nutrition information and planning,         shopping lists and other home organization related activities;     -   as an interface to auctions and online shopping, and where the         system can manage payment or an electronic wallet;     -   management of network communications and conferencing, including         telecommunications, email, instant messaging, Voice over IP         communications and conferencing, local and wide area video and         audio conferencing, pages and alerts;     -   location, selection, management of play lists and play control         of interactive entertainment from local or network sources         including, video on demand, digital audio, such as MP3 format         material, interactive games, web radio and video broadcasts;     -   organization and calendar management for families, businesses         and other groups of users including the management of, meetings,         appointments, and events; and     -   interactive educational programs using local and network         material, with lesson material level set based on user's         profile, and including, interactive multimedia lessons,         religious instruction, calculator, dictionary and spelling,         language training, foreign language translation and         encyclopedias and other reference material.

It will be appreciated that the foregoing statements of the features of the invention are not intended as exhaustive or limiting, the proper scope thereof being appreciated by reference to this entire disclosure and reasonably apparent variations and extensions thereof.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described by reference to the preferred and alternative embodiments thereof in conjunction with the drawings in which:

FIG. 1 is an overall diagrammatic view according to one embodiment of the invention;

FIG. 2 is a schematic block diagram showing the agent architecture according to one embodiment of the invention;

FIG. 3 is a high level process for receiving natural language speech-based queries and/or commands and generating a response according to one embodiment of the invention;

FIG. 4A is a process for receiving natural language speech-based queries and/or commands and generating a response according to one embodiment of the invention;

FIG. 4B is a process for receiving natural language speech-based commands in order to locally or remotely control functions of devices according to one embodiment of the invention;

FIG. 5 is a process for correctly interpreting a user's utterance according to one embodiment of the invention; and

FIG. 6 is a process for determining the proper domain agents to invoke and the properly formatted queries and/or commands that is to be submitted to the agents according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The fact that most natural language queries are incomplete in their definition is a significant barrier to natural human query-response interaction between humans and machines. Further, some questions can only be interpreted in the context of previous questions, knowledge of the domain, or the user's history of interests and preferences. Thus, some natural language questions may not be easily transformed to machine processable form. Compounding this problem, many natural language questions are ambiguous or subjective. In these cases, the formation of a machine processable query and returning of a natural language response is difficult at best.

In order for machines (e.g., computer devices) to properly respond to a question or a command that is in a natural language form, machine processable queries and commands may be formulated after the natural form question or command has been parsed and interpreted. Depending on the nature of the question or command, there may not be a simple set of queries and commands that will return an adequate response. Several queries and commands may need to be initiated and even these queries and commands may need to be chained or concatenated to achieve a complete result. Further, no single available source may contain the entire set of results required. Thus multiple queries and/or commands, perhaps with several parts, may be needed for multiple data sources, which can be both local or on a network. Not all of these sources, queries and/or commands will return useful results or any results at all. Useful results that are returned are often embedded in other information, and from which they may need to be extracted. For example, a few key words or numbers often need to be “scraped” from a larger amount of other information in a text string, table, list, page or other information. At the same time, other extraneous information such as graphics or pictures needs to be removed to process the response. In any case, the multiple results must be evaluated and combined to form the best possible answer, even in the case where some queries do not return useful results or fail entirely. In cases where the question is ambiguous or the result inherently subjective, determining the best result to present is a complex process. Finally, to maintain a natural interaction, responses need to be returned rapidly to the user. Managing and evaluating complex and uncertain queries while maintaining real-time performance is a significant challenge.

The following detailed description refers to the accompanying drawings, and describes exemplary embodiments of the present invention. Other embodiments are possible and modifications may be made to the exemplary embodiments without departing from the spirit, functionality and scope of the invention. Therefore, the following detailed descriptions are not meant to limit the invention.

The present invention provides a complete speech-based information query, retrieval, processing and presentation environment. In addition, the invention may be useful for control of the system itself and/or external devices. This integrated environment makes maximum use of context, prior information and domain and user specific profile data to achieve a natural environment for one or more users making queries or stating commands in multiple domains. Through this integrated approach, a complete speech-based natural language query, command and response environment may be created. FIG. 1 shows a schematic diagram view of a system 90 according to an embodiment of the invention.

The system 90 may include a main unit 98 and a speech unit 128. Alternatively, the system 98 may only comprise of the main unit 98, the speech unit 128 being a completely separate system. The event manager 100 may mediate interactions between other components of the main unit 98. The event manager 100 provides a multi-threaded environment allowing the system 98 to operate on multiple commands or questions from multiple user sessions without conflict and in an efficient manner, maintaining real-time response capabilities.

Agents 106 contain packages of both generic and domain specific behavior for the system 98. Agents 106 may use nonvolatile storage for data, parameters, history information, and locally stored content provided in the system databases 102 or other local sources. User specific data, parameters, and session and history information that may determine the behavior of agents 106 are stored in one or more user profiles 110. Data determining system personality characteristics for agents are stored in the one or more personality module 108. The update manager 104 manages the automatic and manual loading and updating of agents 106 and their associated data from the Internet 136 or other network through the network interface 116.

The main user interface for the system 90, according to an embodiment of the invention, is through one or more speech units 128. The speech unit 128 includes one or more microphones, for example array microphone 134, to receive the utterances of the user. The speech received at the microphone 134 may be processed by filter 132 and passed to the speech coder 138 for encoding and compression. In one embodiment, a transceiver module 130 transmits the coded speech to the main unit 98. Coded speech received from the main unit 98 is detected by the transceiver 130, then decoded and decompressed by the speech coder 138 and annunciated by the speaker 136.

The one or more speech units 128 and the main unit 98 may communicate over a communication link. The communication link can include a wired or wireless link. According to one embodiment, the communication link comprises an RF link. The transceiver 130 on the speech unit communicates coded speech data bi-directionally over the communication link with the transceiver 126 on the main unit 98. According to another embodiment, RF link may use any standard local area wireless data protocols including the IEEE 802.11, Bluetooth or other standards. Alternatively, an infrared data link conforming to any suitable standard such as IrDA or other infrared standards can be used. In an alternative embodiment, wires connect the speech unit 128 and the main unit 98, eliminating the need for one speech coder 138. Other wired or wireless analog or digital transmission techniques can be used.

Coded speech received at the transceiver 126 on the main unit 98 is passed to the speech coder 122 for decoding and decompression. The decoded speech is processed by the speech recognition engine 120 using data in the dictionary and phrases module 112 and received from the agents 106. The recognized words and phrases are processed by the parser 118, which transforms them into complete commands and questions using data supplied by an agent[s] 106. The agent[s] 106 then process the commands or questions. The agent[s] 106 create queries to local databases 102 or though the network interface 116 to data sources on the Internet 136 or other networks. Commands typically result in actions taken by the system 90 itself (i.e., pause or stop), or to a remote device or data source (i.e., download data or program, or control a remote device), through the network interface to the Internet or other data interface.

The agents 106 return results of questions as responses to users. The response may be created using the results of information queries, the system personality 108 and the user preferences or other data in the user profile 110. The agents 106 generally present these results using the speech unit 128. The agents 106 create a response string, which is sent to the text to speech engine 124. The text to speech engine 124 creates the required utterances, which may be encoded and compressed by the speech coder 122. Once coded, the utterances are transmitted from the main unit 98 by the transceiver 126 to the transceiver 130 on the speech unit 128. The utterance is then decoded and decompressed by the speech coder 138 and output by the speaker 136.

The graphical user interface 114 can be used as a substitute or complement to the speech interface. For example, the graphical user interface 114 can be used to view and interact with graphical or tabular information in a manner more easily digested by the user. The graphical user interface can show system state and history in a more concise manner than the speech interface. Users can use the graphical user interface to create or extend agents 106. These operations can include scripting of agents, adding data to the agent or databases 102 used by the agent, adding links to information sources.

The system 90 may comprise of different types of agents. In one embodiment of the invention, generic and domain specific behavior and information may be organized into domain agents. A system agent, on the other hand, provides default functionality and basic services. The domain specific agents provide complete, convenient and re-distributable packages or modules for each application area. In other words, a domain agent includes everything needed to extend or modify the functionality of the system 90 in a current or new domain. Further, domain agents and their associated data can be updated remotely over a network as new behavior is added or new information becomes available. Domain agents may use the services of other, typically more specialized, agents and the system agent. Agents are distributed and redistributed in a number of ways including on removable storage media, transfer over networks or attached to emails and other messages. The invention may provide license management capability allowing the sale of agents by third parties to one or more users on a one time or subscription basis. In addition, users with particular expertise may create agents, update existing agents by adding new behaviors and information, and make these agents available to other users. A block diagram of an agent architecture according to an embodiment of the invention is shown in FIG. 2.

Agents 106 receive and return events to the event manager 100. Both system agents 150 and domain agents 156 receive questions and commands from the parser 118. Based on keywords in the questions and commands and the structures of the questions and commands, the parser invokes the required agent[s]. Agents use the nonvolatile storage for data, parameters, history information and local content provided in the system databases 102. When the system starts-up or boots-up the agent manager 154 may load and initialize the system agent 150 and the one or more domain agents 156. At shutdown the agent manager unloads the agents. The agent manager 154 also performs license management functions for the domain agents 156 and content in the databases 102.

The system agent 150 manages the criteria handlers 152, which handle specific parameters or values (criteria) used to determine context for questions and commands. Both the system agent 150 and the domain agents 156 use the criteria handlers 152. The various domain agents 156 can use the services of the system agent 150 and of other, typically more specialized, domain agents 156. The system agent 150 and the domain agents 156 use the services of the agent library 158, which contains utilities for commonly used functions. The library may include utilities for text and string handling, network communications, database lookup and management, fuzzy and probabilistic evaluation, text to speech formats, and other utilities.

Domain agents 156 can be data-driven, scripted or created with compiled code. A base of generic agent is used as the starting point for data-driven or scripted agents. Agents created with compiled code are typically built into dynamically linkable or loadable libraries. Developers of agents can add new functionality to the agent library 158 as required. Details of agent distribution and update, and agent creation or modification are discussed in sections below.

The invention, according to another embodiment of the invention, may provide capabilities to distribute and update system agents 150, domain agents 156, agent library components 158, databases 102, and dictionary and phrase entries 112 over wireless or wired networks 136, including dial-up networks using the update manager 104. The network interface 116 may provide connections to one or more networks. The update manager 104 may also manages the downloading and installation of core system updates. The agent manager 154 may perform license management functions for the domain agents and the databases. The update manager 104 and agent manager 154 may perform these functions for all agents and database content including, agents and content available to all users or agents and content only available to certain users. Examples of agent and database components added or updated on a periodic basis include:

-   -   agents for new domains;     -   additional domain knowledge for agents;     -   new keywords for a domain, which can include names of         politicians, athletes, entertainers, names of new movies or         songs, etc. who have achieved recent prominence;     -   links to a preferred set of information sources for the domains         covered including links for, entertainment, news, sports,         weather, etc.;     -   updates to domain information based on, for example, changes to         tax laws, company mergers, changing political boundaries;     -   updates to content, including dictionaries, encyclopedias and         almanacs; and     -   other content and database components.

When a user requires or selects a new domain agent 156 or database element 102, the update manager 104 may connect to their source on the network 136 though the network interface 116, download and install the agent or data. To save system resources and to comply with any license conditions, the update manager 104 may uninstall agents that are no longer in use. In one embodiment of the invention, the update manager 104 periodically queries one or more sources of the licensed agents and database components to locate and download updates to agent executables, scripts or data as they become available. Alternatively, the agent sources may initiate the downloading of agent updates of the registered or licensed agents to the update manager as they become available.

The agent manager 154 may provide a license management client capable of executing most any license terms and conditions. When a particular agent 106 and/or database element 102 is required by a command, the agent manager 154 verifies that the use of the agent or data element is within the allowed terms and conditions, and if so, invokes the agent or allows access to the data element. License management schemes that can be implemented through the agent manager 154 include outright purchase, subscription for updates, one time or limited time use. Use of shared agents and data elements (such as those downloaded from web sites maintained by groups of domain experts) may also be managed by the agent manager 154.

If a question or command requires an agent, currently not loaded on the system, the agent manager 154 may search the network 136 through the network interface 116 to find a source for a suitable agent. Once located, the agent can be loaded under the control of the update manager 104, within the terms and conditions of the license agreement as enforced by the agent manger.

New commands, keywords, information, or information sources can be added to any domain agent 156 by changing agent data or scripting. These configuration capabilities may allow users and content developers to extend and modify the behavior of existing domain agents 156 or to create new domain agents 156 from a generic agent without the need to create new compiled code. Thus, the modification of the domain agents 156 may range from minor data-driven updates by even the most casual users, such as specifying the spelling of words, to development of complex behavior using the scripting language as would typically be done by a domain expert. The user can create and manage modifications to domain agents 156 through speech interface commands or using a graphical user interface 114. User-specific modifications of domain agents 156 are stored in conjunction with the user's profile 110 and accessed by the domain agent 156 at run-time.

The data used to configure data driven agents 156 are structured in a manner to facilitate efficient evaluation and to help developers with organization. These data are used not only by the agents 156, but also by the speech recognition engine 120, the text to speech engine 124, and the parser 118. Examples of some major categories of data include:

1. Content packages include questions or commands. Each command or question or group of commands or questions includes contexts used for creation of one or more queries. The agent 156 passes a regular grammar expression to the parser 118 for evaluation of a context or question. An initial or default context is typically supplied for each command or question. The command or question includes a grammar for the management and evaluation of the context stack.

2. Page lists or pointers to other local or network content sources. For each page or content source there is a pointer (e.g. URL, URI, or other pointer) to the page or source. Each page has specific scraping information used to extract the data of interest. The scraping information includes matching patterns, HTML or other format parsing information.

3. A response list, determining the response of the agent 156 to a particular command or question given the context, the user profile and the information retrieved. Responses can include diagnostic error messages or requests for more information if the question or command cannot yet be resolved from the known information. Responses can be based on or dependent on thresholds or probabilistic or fuzzy weights for the variables.

4. Substitution lists containing variable substitutions and transformations, often applied by the agents 150, 156 in the formatting of queries and results. For example, a stock domain specific agent 156 would use a substitution list of company trading symbols, company names and commonly used abbreviations. Substitutions and transformations can be performed on commands and questions to create precise queries, which can be applied against one or more information sources or to results for creating more meaningful output to the user. Substitution lists also include information for optimally dealing with structured information, such as HTTP formatted page parsing and evaluation.

5. Personalities used for responses. Personalities are constructed by combining multiple traits in a weighted manner. Weights can be specified for each agent's domain area to create one or more specific personalities. Examples of personality traits include sarcasm, humor, irritation, and sympathy, and other traits.

6. Public and user specific parameters for sources, substitutions, transformations, variables or criteria. The public parameter lists are part of the agent package 156. The user specific parameters are contained in the user profile 110.

Commands and questions are interpreted, queries formulated, responses created and results presented based on the users personal or user profile 110 values. Personal profiles may include information specific to the individual, their interests, their special use of terminology, the history of their interactions with the system, and domains of interest. The personal profile data may be used by the agents 106, the speech recognition engine 120, the text to speech engine 124, and the parser 118. Preferences can include, special (modified) commands, past behavior or history, questions, information sources, formats, reports, and alerts. User profile data can be manually entered by the user and/or can be learned by the system 90 based on user behavior. User profile values may include:

-   -   spelling preferences;     -   date of birth for user, family and friends;     -   income level;     -   gender;     -   occupation;     -   location information such as, home address, neighborhood, and         business address;     -   car type;     -   telecommunications and other service providers and services;     -   financial and investment information;     -   synonyms (i.e., a nick name for someone);     -   special spelling;     -   keywords;     -   transformation or substitution variables;     -   domains of interest; and     -   other values.

End users may use the data driven agent 156 extension and modification facilities and values stored in user profiles 110 to create special reports, packages of queries, alerts and output formats. A single alert or report can be configured to use multiple data sources, values, and other variables (i.e., time, location, etc.) to condition or otherwise determine when an alert should be sent. For example, an alert can be generated by sampling a stock price every fifteen minutes and sending an alert if the price drops below some value. To create a report, the user first specifies a set of commands or questions. Next, the user creates or selects a format for the report. Finally the user may name the report. A report can have variable parameters. For example, a user may create a company stock report, and execute the report by stating its name and the company name, which gives the user selected information and in a specified format for that company. In another example, a user can create a “morning” report, which presents selected multimedia information from different sources (news, sports, traffic, weather) in the order and formats desired. Alerts and reports can be created using only voice commands and responses, commands and responses through the graphical user interface 114, or a combination of the two. To create a report, alert, or other specialized behavior, the user performs a number of steps including:

-   -   specify the command to run a report or alert;     -   specify the question or questions, including keywords, used for         a query;     -   set the criteria for running the report such as on command or         when a particular condition is met;     -   define preferred information sources;     -   define preferences for order of result evaluation by source,         value, etc.;     -   specify the presentation medium for a report or alert, such as         an email, the text to speech engine, a message to a pager, or a         text and graphics display; and     -   specify the preferred format for the report, such as information         to be presented, order of information to be presented, preferred         abbreviations or other variable substitutions.

Filtering and noise elimination may be important in facilitating the various functionalities of the system 90. The accurate recognition and parsing of the user's speech requires the best possible signal to noise ratio at the input to the speech recognition engine 120. To accomplish the required improvements an array microphone 134 and a filter 132 are employed. According to an embodiment of the invention, the microphone array, filters and speech coder 138 are physically separated from the main unit 98 into a speech unit 128, and connected using a wireless link. Since bandwidth on a wireless connection is at a premium, the speech coder dynamically adapts the digitization rate and compression of the captured speech.

The speech unit 128 may use an array of microphones 134 to provide better directional signal capture and noise elimination than can be achieved with a single microphone. The microphone array can be one-dimensional (a linear array) or two-dimensional (a circle, square, triangle or other suitable shape). The beam pattern of the array can be fixed or made adaptive though use of analog or digital phase shifting circuitry. The pattern of the active array is steered to point in the direction of the one or more users speaking. At the same time nulls can be added to the pattern to notch out point or limited area noise sources. The use of the array microphone also helps reduce the cross talk between output from the text to speech engine 124 through the speaker 136 and detection of the user's speech.

The microphone can be complemented with an analog or digital (i.e., Voice over IP) speech interface. This interface allows a remote user to connect to the system and interact with it in the same manner possible if they were physically present.

The speech unit 128, according to an embodiment of the invention, may use an analog or digital filter 132 between the array microphone 134 and the speech coder 138. The pass band of the filter is set to optimize the signal to noise ratio at the input to the speech recognition engine 120. In some embodiments, the filter is adaptive, using band shaping combined with notch filtering to reject narrow-band noise. In one embodiment of the invention, the system 90 may employ adaptive echo cancellation in the filter. The echo cancellation helps prevent cross talk between output from the text to speech engine and detection of the user's speech as well as suppression of environmentally caused echoes. Algorithms comparing the background noise to the signal received from the user's speech are used to optimize the band-shaping parameters of the adaptive filter. Those skilled in the art will be familiar with multiple techniques used to construct suitable digital and analog filters.

The speech received by the array microphone 134 and passed through the filter 132 may be sent to the speech digitizer or coder 138. The speech coder 138 may use adaptive lossy audio compression to optimize bandwidth requirements for the transmission of the coded speech to the speech recognition engine 120 over a wireless link. The lossy coding may be optimized to preserve only the components of the speech signal required for optimal recognition. Further, the lossy compression algorithms that may be used may be designed to prevent even momentary gaps in the signal stream, which can cause severe errors in the speech recognition engine. The digitized speech may be buffered in the coder and the coder may adapt the output data rate to optimize the use of the available bandwidth. The use of the adaptive speech coder is particularly advantageous when a band-limited wireless link is used between the coder and the speech recognition engine 120.

In an alternative embodiment, the array microphone can be replaced by a set of physically distributed microphones or a headset worn by the user. The distributed microphones can be placed in different parts of a room or in different rooms. The distributed microphones can create a three-dimensional array to improve signal to noise ratio. The headset may use a wireless or wired connection.

While the invention is intended to be able to accept most any natural language question or command, ambiguity can still be a problem. To assist users in formulating concise questions and commands, the system 90 may support a voice query language. The language is structured to allow a variety of queries with minimal ambiguity. Thus, the voice query language helps users clearly specify the keywords or contexts of the question or command along with the parameters or criteria. The language provides a grammar to clearly specify the keyword used to determine the context and a set of one or more criteria or parameters. A user asking a question or stating a command in the voice query language is nearly always guaranteed to receive a response.

The voice query language may be sensitive to the contents of the context stack. Thus, a following-on question can be asked using an abbreviated grammar, since keywords and criteria can be inherited from the stack. For example, the user can simply ask about another keyword if the criteria of the question remain constant.

The system 90 may provide built in training capabilities to help the user learn the best methods to formulate their questions and commands. The interactive training allows the user to audibly or visibly see the machine interpretation of their queries and provides suggestions on how to better structure a query. Using the interactive training a user can quickly become comfortable with the voice query language and at the same time learn how to optimize the amount of information required with each step of a dialog.

The output of the speech coder 122 may be fed to the speech recognition engine 120. The speech recognition engine 120 recognizes words and phrases, using information in the dictionary and phrase tables 112, and passes these to the parser 118 for interpretation. The speech recognition engine 120 may determine the user's identity by voice and name for each utterance. Recognized words and phrases may be tagged with this identity in all further processing. Thus, as multiple users engage in overlapping sessions, the tags added by the speech recognition engine 120 to each utterance allows other components of the system 90 to tie that utterance to the correct user and dialog. The user recognition capability may further be used as a security measure for applications, such as auctions or online shopping, where this is required. Voice characteristics of each user may be contained in the user profile 110.

A user may start a dialog with the system 90 when they first address it. This can be done by speaking a generic word (“computer”) or addressing a specific name (“Fred”), which may be generally tied to a system personality 108. Once the user starts the dialog, it may be recognized by the speech recognition engine 120, using unique characteristics of the user's speech. At the end of a dialog or to interrupt a dialog, the user may utter a dismissal word (“good bye”).

According to another embodiment of the invention, the system 90 may employ a speech recognition engine 120 seeding for improved word recognition accuracy, using data from the dictionary and phrase tables 112, user profiles 110, and the agents 106. At the same time, the fuzzy set possibilities or prior probabilities for the words in the dictionary and phrase tables may be dynamically updated to maximize the probability of correct recognition at each stage of the dialog. The probabilities or possibilities may be dynamically updated based on a number of criteria including the application domain, the questions or commands, contexts, the user profile and preferences, user dialog history, the recognizer dictionary and phrase tables, and word spellings.

For uncommon words or new vocabulary words, a user may be given the option to spell the words. The spelling may be done by saying the names or the letters or using a phonetic alphabet. The phonetic alphabet can be a default one or one of the user's choosing.

Alternatively, when a user uses a word that is not recognized at all or is not correctly recognized by the speech recognition engine 120 then the user may be asked to spell the word. The speech recognition engine 120 determines this condition based on confidence level for the scoring process. The word is looked up in the dictionary 112 and the pronunciation for the word is added to either the dictionary, the agent 106, or the user's profile 110. The word pronunciation can then be associated with the domain, the question, the context and the user. Though this process the speech recognition engine learns with time and improves accuracy. To assist users in spelling words an individualized phonetic alphabet can be used. Each user can modify the standard phonetic alphabets with words, which they can remember more easily.

Once the words and phrases have been recognized by the speech recognition engine 120, the tokens and user identification is passed to the parser 118. The parser 118 examines the tokens for the questions or commands, context and criteria. The parser 118 determines a context for an utterance by applying prior probabilities or fuzzy possibilities to keyword matching, user profile 110, and dialog history. The context of a question or command determines the domain and thereby, the domain agent 156, if any, to be evoked. For example, a question with the keywords “temperature” implies a context value of weather for the question. The parser dynamically receives keyword and associated prior probability or fuzzy possibility updates from the system agent 150 or an already active domain agent 156. Based on these probabilities or possibilities the possible contexts are scored and the top one or few are used for further processing.

The parser 118 uses a scoring system to determine the mostly likely context or domain for a user's question and/or command. The score is determined from weighting a number of factors, including the user profile 110, the domain agent's data content, and previous context. Based on this scoring, the system 90 invokes the correct agent. If the confidence level of the score is not high enough to ensure a reliable response, the system 90 may ask the user to verify whether the question and/or command is correctly understood. In general, the question that is asked by the system 90 may be phrased to indicate the context of the question including all criteria or parameters. For example, the question can be in the form of: “Did I understand that you want such-and-such?” If the user confirms that the question is correct the system proceeds to produce a response. Otherwise, the user can rephrase the original question, perhaps adding additional information to remove ambiguity, or the system can ask one or more questions to attempt to resolve the ambiguity.

Once the context for the question or command has been determined, the parser 118 can invoke the correct agent 156, 150. To formulate a question or command in the regular grammar used by agents, the parser 118 may determine required and optional values for the criteria or parameters. These criteria may have been explicitly supplied by the user or may need to be inferred. The parser 118 makes use of the criteria handlers 152 supplied by the system agent 150. The criteria handlers 152 provide context sensitive procedures for extracting the criteria or parameters from the user's question or command. Some criteria are determined by executing algorithms in the agent, while others may be determined by applying probabilistic of fuzzy reasoning to tables of possible values. Prior probabilities or fuzzy possibilities and associated values are received from a number of sources including the history of the dialog, the user profile 110, and the agent. Based on user responses, the prior probabilities or fuzzy possibilities are updated as the system learns the desired behavior. For a weather context, examples of criteria include, location, date and time. Other criteria can include command criteria (i.e., yes/no, on/off, pause, stop), and spelling. Special criteria handlers are available from the system agent for processing lists, tables, barge-in commands, and long strings of text and system commands.

The criteria handlers 152 operate iteratively or recursively on the criteria extracted to eliminate ambiguity. This processing helps reduce the ambiguity in the user's question or command. For example, if the user has a place name (or other proper noun) in their utterance the parser 118 can use services of the domain agent 156 to look up tables in the databases 102 for place names or can attempt to determine which word is the proper noun from the syntax of the utterance. In another example, the user asks “what about flight one hundred and twenty too?.” The parser and domain agent use flight information in the database and network information along with context to determine the most plausible interpretation among; flight 100 and flight 20 also, flight 100 and flight 22, flight 122, and the like.

Once the context and the criteria are determined, the parser 118 may form the question or command in a standard format or hierarchical data structure used for processing by the agents 150, 156. The parser 118 may fill in all required and some optional tokens for the grammar of the context. Often the tokens must be transformed to values and forms acceptable to the agents. The parser obtains the required transformations from the agents, dialog history or user profile 110. Examples of transformations or substitutions performed by the parser on tokens include:

-   -   substituting a stock symbol for a company name or abbreviation;     -   substituting a numerical value for a word or words;     -   adding a zip code to an address; and     -   changing a place or other name to a commonly used standard         abbreviation.

The agents 150, 156 may receive a command or question once the parser 118 has placed it in the required standard format. Based on the context, the parser 118 evokes the correct agent to process the question or command.

Commands can be directed to the system 90 or to an external entity. System commands are generally directed to the system agent 150. Commands for external entities are generally processed by a domain agent 156, which includes the command context and behavior for the external entity.

Specific questions are generally directed to one of the domain agents 156. Based on the question or context and the parameters or criteria, the domain agent creates one or more queries to one or more local or external information sources. Questions can be objective or subjective in nature. Results for objective questions can often be obtained by structured queries to one or more local or network information sources. Even for objective questions, the system 90 may need to apply probabilistic or fuzzy set analysis to deal with cases of conflicting information or incomplete information. Information to answer subjective questions is generally obtained by one or more ad-hoc queries to local or network data sources, followed by probabilistic or fuzzy set evaluation of the one results to determine a best answer.

Once the domain agent 156 has formulated the one or more queries, they may be sent to local and/or network information sources. The queries are performed in an asynchronous manner to account for the fact that sources respond at different speeds or may fail to respond at all. Duplicate queries are sent to different information sources to ensure that at least one source responds with a useful result in a timely manner. Further, if multiple results are received in a timely manner, they can be scored by the system to determine which data is most reliable or appropriate. Examples of data sources accommodated include, HTTP data sources, sources with meta-data in various formats including XML, entertainment audio, video and game files including MP3, databases using query languages and structured responses such as SQL, and other data sources.

The local information sources can be stored in one or more system databases 102 or can be on any local data storage such as a set of CDs or DVDs in a player or other local data storage. Network information sources can be connected to the Internet 136 or other network and accessed through a series of plug-ins or adaptors, known as pluggable sources, in the network interface 116. The pluggable sources in the network interface 116 may be capable of executing the protocols and interpreting the data formats for the data sources of interest. The pluggable sources may provide information scraping data and procedures for each source to the domain agents 156. If a new type of data source is to be used, a new plug-in or adaptor can be added to the network interface 116.

The domain agent 156 evaluates the results of the one or more queries as they arrive. The domain agent 156 scores the relevance of the results based on results already received, the context, the criteria, the history of the dialog, the user profile 110 and domain specific information using probabilistic or fuzzy scoring techniques. Part of the dialog history is maintained in a context stack. The weight of each context for the scoring is based on the relevance of one context to another and the age of the contexts. Other scoring variables can be associated through the context stack. Contexts can also be exclusive, so that previous contexts have no weight in the scoring.

Based on the continuous scoring processes, the domain agent 156 may determine if a single best answer can be extracted. For most questions the desired result has a set of tokens that must be found to formulate an answer. Once a value has been found for each of these tokens the results are ready for presentation to the user. For example, for a question on weather, the tokens can include the date, day of week, predicted high temperature, predicted low temperature, chance of precipitation, expected cloud cover, expected type of precipitation and other tokens. Results processed in this manner include error messages. For subjective questions this determination is made by determining a most likely answer or answers, extracted by matching of the results received. If no satisfactory answer can be inferred from the results of the query the agent can do one of the following:

1. Ask the user for more information, typically through the speech interface, and based on the results obtained formulate new queries. This approach is applied when an irresolvable ambiguity arises in the formulation of a response.

2. Formulate new queries based on the results received from the first set of queries. This approach is typically applied in cases where the responses received do not contain all the required information. Information sources to query can be inferred from the results already obtained (i.e., links in an HTML document) or from other sources. Using this approach one or more sets of queries and responses can be chained without the need for action by the user.

3. Wait for additional queries to return results.

In any case, the domain agent 156 may continue to make queries and evaluate results until a satisfactory response is constructed. In doing so, the agent can start several overlapping query paths or threads of inquiry, typically mediated by the event manager 100. This technique, combined with the use of asynchronous queries from multiple data sources provides the real-time response performance required for a natural interaction with the user.

The domain agent 156 may apply conditional scraping operations to each query response as it is received. The conditional scraping actions depend on the context, the criteria, user profile 110, and domain agent coding and data. For each token to be extracted, scraping criteria 152 may be created using the services of the system agent 150. The scraping criteria use format specific scraping methods including, tables, lists, text, and other scraping methods. One or more scraping criteria can be applied to a page or results set. Once additional results are received, the domain agent 156 can create new scraping criteria to apply to results already acquired. The conditional scraping process removes extraneous information, such as graphics, which need not be further processed or stored, improving system performance.

The domain agent 156 may strongly influence how the results are presented. For instance, once the domain agent 156 has created a satisfactory response to a question, the agent 156 may format that response for presentation. Typically, the domain agent 156 formats the response into the markup format used by the text to speech engine 124. The domain agent 156 may also format the result presentation using available format templates and based on the context, the criteria, and the user profile 110. Variable substitutions and transformations may be performed by the agent 156 to produce a response best understood and most natural to the user. Further, the order of presentation of tokens and the exact terminology used to create a more natural response to the user may be varied by the agent 156. The domain agent 156 may also select the presentation personality 108 to be used.

The domain agent 156, may select the presentation template, determine order of presentation for tokens and determine variable substitutions and transformations using probabilistic or fuzzy set decision methods. The template used to form the presentation can be from the domain agent itself or from the user profile 110. The user profile 110 can completely specify the presentation format or can be used to select and then modify an existing presentation format. Selection and formatting of presentation template can also depend on the presentation personality modules 108. At the same time, the characteristics of the personality used for the response are dynamically determined using probabilities or fuzzy possibilities derived from the context, the criteria, the domain agent itself and the user profile 110.

The domain agent 156 may apply a number of transformations to the tokens before presentation to the user. These variable substitutions and transformations are derived from a number of sources including, domain information carried by the agent, the context, the token values, the criteria, the personality module 108 to be used, and the user profile 110. Examples of variable substitutions and transformations include:

-   -   substitution of words for numbers;     -   substitution of names for acronyms or symbols (i.e., trading         symbols);     -   use of formatting information derived from the information         sources (i.e., HTML tags);     -   nature of the response including, text, long text, list, table;     -   possible missing information or errors;     -   units for measurement (i.e., English or metric); and     -   preferred terminology from the user profile 110 or presentation         personality 108.

The system 90, according to another embodiment of the invention, may provide special purpose presentation capabilities for long text strings, tables, lists and other large results sets. Domain agents 156 may use special formatting templates for such results. The system agent 150 may provide special criteria handlers 152 for presentation and user commands for large results sets. The presentation templates used by the domain agents 156 for large results sets typically include methods for summarizing the results and then allowing the user to query the result in more detail. For example, initially only short summaries, such as headlines or key numbers, are presented. The user can then query the results set further. The criteria handlers 152 provide users with the capability to browse large results sets. Commands provided by the criteria handlers 152 for large results sets include, stop, pause, skip, rewind, start, and forward.

Some information, in formats such as video, pictures and graphics, may be best presented in a displayed format. The domain agents 156 may apply suitable presentation templates in these cases and present the information through the graphical user interface 114. The system agent 150 provides special criteria handlers 152 for presentation and user commands for display presentation and control.

FIG. 3 is a high level process 300 for receiving natural language speech-based queries and/or commands and generating a response according to an embodiment of the invention. The process 300 comprises of individual steps, several of which may be repetitive in order to accommodate partial failures. The process 300 may begin when a user's utterance is received and processed at 302. The user utterance may be a query and/or a command and may be of a natural language speech-based form. After receiving the natural language query and/or command, the query and/or command may be processed so that the data is in a more machine understandable format such as in a digital format. Once the utterance has been converted into an understandable format, the utterance may be processed so that at least an approximate meaning of the utterance can be determined at 304. This may be accomplished by, for example, the use of stored dictionaries, phrases, user profiles, domain agent data, and other data. Based on the approximate meaning of the utterance, one or more correctly formatted queries and/or commands may be generated. A user created query and/or command may require that multiple queries and/or commands may be needed in order to generate the desired response or action. Further, depending upon the context (e.g., who is the user, what is the subject of the query and/or command directed to, at what time or location is the query and/or command being directed to, and other parameters used in defining the query and/or command) in which the query and/or command has been submitted, a specific format for the query and/or command may be required. For instance, each of the domain agents 156 may require that queries and/or commands be formatted in a specific manner. Thus at 306, one or more properly formatted queries and/or commands may be generated. Steps 304 and 306 may be operations which may have to be repeated in order to obtain the correct interpretation of the user utterance and result in the desired response and/or action. Once the properly formatted queries and/or commands are generated, the appropriate action may be taken at 308. This may require that the properly formatted queries and/or commands be sent to specific domain agent[s], information source[s], device[s], or other appropriate destination[s] that can fulfill the requirements of the query and/or command. Once the appropriate action[s] have been executed, this event may be recorded to, for example, the user's profile, database and/or one or more agents at 310. Such data may be useful for future user inquires and commands. After the action[s] have been performed, a response, if need be, may be generated and forwarded to the user and/or third parties at 312. In the case of a query for retrieving data, the response would contain the requested information. In the case of a command, the response may be a confirmation that a specific action[s] has been executed. The response may be in the form of a natural language format. The response may also be formatted to reflect a particular personality or tone to the response in order to make the response more “human.” The response may be relayed to the user and/or third parties as an audio message and/or a visual message displayed on a user interface.

FIG. 4A is a process 400 for receiving natural language speech-based queries and/or commands and generating a response using the system 90 according to another embodiment of the invention. The process 400 may begin when a user's utterance (i.e., user query and/or command) is captured through accurate speech recognition operating in a variety of real-world environments at 402. Once the utterance is captured, it is parsed and interpreted to determine the query and/or command that is contained in the utterance at 404. Next, review of the query and/or command and determine the domain of expertise required and the context of the query, invoking the proper resources including, for example, agents at 406. The original query and/or command submitted by the user will often require that multiple queries and/or commands be generated. For instance, suppose a user is interested in retrieving the value of her stock portfolio. The user may utter “please get the value of my stock portfolio.” The system 90 may review this request together with stored data such as the user's profile and determine keywords such as “get the value” and “my stock portfolio.” The system 90 may then generate queries to determine the stocks in the user's portfolio, the number of shares and the source for current pricing information. These queries may then be sent to one or more agent domains, such as a domain which may access a database containing the user's profile and a domain which accesses stock pricing sources to determine the answers to these questions. Queries may be sent to these domain agents or sources in order to obtain the desired data. Thus, at 408 formulate one or more queries that are sent to one or more local and/or network data sources and/or send appropriate commands to local or remote devices or the system itself. The queries are then sent to the designated agent[s]. The agents may then, in turn, generate their own queries and/or commands to be sent to, for example, local or remote information sources to retrieve needed data. The agent generated queries and/or commands may be formatted according to the requirements of the target sources and variable substitutions and transformations are performed to modify the queries to a form most likely to yield desired results from the available sources at 410. Once the queries are formatted correctly, they may be executed in an asynchronous manner and dealing gracefully with failures at 412. As a result of the execution of the queries, results may be returned by the domain agents and/or sources. The system 90 may then extract or scrape the desired information from the one or more results, which may be returned in any one of a number of different formats at 414. That is, the results sought by a user may be the summary or the results of further processing of information obtained from several sources for example. Next, the results may be evaluated and interpreted including processing of errors, and gathering and combining them into a single best result judged to be “best” even if the results are ambiguous, incomplete, or conflicting at 416. Once the best results are determined, perform any required formatting, variable substitutions and transformations to modify the results to a form most easily understood by the user at 418. Finally, the compound results may be presented through the text to speech engine 124, to the user in a useful and expected manner at 420. The process 400 may be performed while accounting for the domain of expertise required, the context in which the question or command is presented, the domain specific information available, the history of the user's interaction, the user preferences, the information sources or commands that are available, and responses obtained from the sources. At each stage of the process 400, probabilistic or fuzzy set decision and matching methods may be applied to deal with inconsistent, ambiguous, conflicting and incomplete information or responses. In addition, the use of asynchronous queries that may result in rapid and graceful failure of some queries or commands may allow the system 90 to robustly return results quickly and in a manner that seems natural to the user.

FIG. 4B is a process 450 for receiving natural language speech-based commands in order to locally or remotely control functions of the system 90 or for other devices according to another embodiment of the invention. The process 450 may begin when a user's utterance (i.e., user query and/or command) is captured through accurate speech recognition operating in a variety of real-world environments at 452. Once the utterance is captured, it is parsed and interpreted to determine the command that is contained in the utterance at 454. Next, the command is reviewed and the domain determined for the command and context, invoking the proper resources, including selecting of agents at 456. The original command submitted by the user will often require that multiple queries and/or commands be generated. For instance, suppose a user is interested in recorded his favorite television program. The user may utter “please record my favorite TV program.” The system 90 may review this request together with stored data such as the user's profile and determine keywords such as “record” and “my favorite TV program.” The system 90 may then generate queries to determine the name, the channel, and time for the user's favorite TV program. These queries may then be sent to a domain agent, which may access a database containing the user's profile and determine the answers to these questions. A command may then be sent to a video recorder ordering the video recorder to record the selected TV program. Thus, at 458 formulate one or more queries that are to be sent to one or more local and/or network data sources and/or send appropriate commands to local or remote devices or the system itself. Next, route the generated commands to the appropriate system[s] and/or external devices at 460. Once the commands have been executed, results including errors may be received and processed at 462. The results of the executed commands may be optionally presented to the user at 464.

Some of the steps depicting in FIG. 4A may actually require multiple steps that may also be repetitive. For instance, in step 404, the user's utterance is parsed and interpreted in order to determine the meaning of the utterance. The system 90 may make an initial interpretation of the utterance based on the data stored in, for example, the dictionary and phrases module 112, user profiles 110, agents 106 and the databases 102. A real-time scoring system or other techniques may be applied to the interpretation results in order to generate a domain or a context score. If the confidence level of the domain or context score is not high enough to ensure a reliable response, the system 90 can request that the user verify the question or command is correctly understood. In general, the question may be phrased to indicate the context of the question including all criteria or parameters. If the user confirms that the question is correct, the system 90 may proceed to produce a response. Otherwise, either the user can rephrase the original question, perhaps adding additional information to remove ambiguity, or the system may ask one or more questions to attempt to resolve the ambiguity or other actions may taken. FIG. 5 is a process 500 for correctly interpreting a user's utterance according to one embodiment of the invention. The process 500 generally represents steps 402 and 404 of process 400. Initially the user's utterance is inputted into the system 90 at 502. The input is then interpreted at 504 using, for example, various sources of stored data such as user profiles, agent data, dictionary and phrases, and other relevant data. The interpretation is then scored using, for instance, a weighted scoring system as described previously at 506. Once a score is obtained, a determination is made as to whether the confidence level of the interpretation is satisfactory at 508. In other words, the determination relates to whether the score or confidence level given to the interpretation exceeds a certain value. If the confidence level is determined to be unsatisfactory then a request may be submitted to the user requesting that the user verify the interpretation at 510 and 512. If the user is unsatisfied with the interpretation, he/she may be asked to rephrase the utterance and/or provide additional information at 514. Once the user provides the rephrased utterance and/or additional information, the process 500 returns to the beginning at 502. If, on the other hand, the user is satisfied with the interpretation, then the process 400 for receiving a natural language speech-based queries and/or commands and generating a response may continue at 516.

Once the meaning of the utterance has been determined, the appropriate domain agent[s] and the query and/or commands properly formatted for the agent[s] may be determined. Referring to FIG. 6, a process 600 is illustrated for determining the proper domain agent[s] to invoke and the proper formatting of queries and/or commands that are to be submitted to the agents 106, as generally depicted in steps 406-408 of FIG. 4A according to one embodiment of the invention. In order to formulate a question or command in the regular grammar used by agents 106, a determination may be made as to the required and optional values for the criteria or parameters of the queries and/or commands. These criteria may have been explicitly supplied by the user or may need to be inferred. Thus, the properly interpreted query and/or command that is generated by, for example, steps 404 and 454 of FIGS. 4A and 4B, is parsed at 602. The content of the properly interpreted query and/or command is then analyzed to determine the criteria and/or parameters of the properly interpreted query and/or command at 604. A context sensitive procedure for extracting the criteria or parameters from the properly interpreted query and/or command may be used. Some criteria are determined by executing algorithms in the agent, while others may be determined by applying probabilistic of fuzzy reasoning to tables of possible values. Prior probabilities or fuzzy possibilities and associated values are received from a number of sources including the history of the dialog, the user profile 110, and the agent. Based on user responses, the prior probabilities or fuzzy possibilities are updated as the system 90 learns the desired behavior. For a weather context, examples of criteria include, location, date and time. Other criteria can include command criteria (i.e., yes/no, on/off, pause, stop), and spelling. The process for determining criteria may be iterative or recursive in order to eliminate ambiguity in the user's question or command. For example, if the user has a place name (or other proper noun) in their utterance, tables in the databases 102 may be reviewed for place names or an attempt may be made to determine which word is the proper noun from the syntax of the utterance. In another example, the user asks “what about flight one hundred and twenty too?” In such a situation, flight information in the database and network information along with context may be used to determine the most plausible interpretation among: flight one-hundred and flight twenty also, flight one-hundred and flight twenty-two, flight one hundred twenty-two, and the like. Once the parameters and criteria for the query and/or command have been established, the proper agents 106 may be selected at 606. After selecting the agents 106, a properly formatted query and/or command that will be submitted to the agents 106 may be determined at 608. The query and/or command may be in a standard format or may be a hierarchical data structure used for processing by the agent 106. In order to submit the properly formatted query and/or command to the agent 106, all of the required and some optional tokens for the grammar of the context may be filled in. Often the tokens must be transformed to values and forms acceptable to the agents. The required transformations may be obtained from the agents, dialog history or user profile 110. Examples of transformations or substitutions that may be performed were provided above. Once the properly formatted queries and/or commands are generated, the process (e.g., process 400) may continue at 610. 

What is claimed is:
 1. A method for filtering and eliminating noise from natural language utterances, comprising: receiving a natural language utterance at a microphone array that adds one or more nulls to a beam pattern steered to point in a direction associated with a user speaking the natural language utterance, wherein the one or more nulls notch out point or limited area noise sources from an input speech signal corresponding to the natural language utterance; comparing environmental noise to the input speech signal corresponding to the natural language utterance to set one or more parameters associated with an adaptive filter coupled to the microphone array; passing the input speech signal corresponding to the natural language utterance to the adaptive filter, wherein the adaptive filter uses band shaping and notch filtering to remove narrow-band noise from the input speech signal corresponding to the natural language utterance according to the one or more parameters; suppressing cross-talk and environmentally caused echoes in the input speech signal corresponding to the natural language utterance using adaptive echo cancellation in the adaptive filter; sending the input speech signal passed through the adaptive filter to a speech coder that uses adaptive lossy audio compression to remove momentary gaps from the input speech signal and variable rate sampling to compress and digitize the input speech signal, wherein the speech coder optimizes the adaptive lossy audio compression and the variable rate sampling to only preserve components in the input speech signal that will be input to a speech recognition engine; and transmitting the digitized input speech signal from a buffer in the speech coder to the speech recognition engine, wherein the speech coder transmits the digitized input speech signal to the speech recognition engine at a rate that depends on available bandwidth between the speech coder and the speech recognition engine.
 2. The method recited in claim 1, wherein the speech coder uses the adaptive lossy audio compression to remove the momentary gaps from the input speech signal to prevent errors in the speech recognition engine.
 3. The method recited in claim 1, wherein the speech coder uses the variable rate sampling to maximize a fidelity associated with the digitized input speech signal and minimize the available bandwidth used to transmit the digitized input speech signal to the speech recognition engine.
 4. The method recited in claim 3, wherein the speech coder adapts a rate associated with digitizing and compressing the input speech signal to minimize the available bandwidth used to transmit the digitized input speech signal to the speech recognition engine.
 5. The method recited in claim 1, wherein the adaptive filter has a pass band set to optimize a signal to noise ratio associated with the components in the input speech signal that will be input to the speech recognition engine.
 6. The method recited in claim 1, wherein a main unit that includes the speech recognition engine and a speech unit that includes the microphone array, the adaptive filter, and the speech coder are physically separate and communicate over a wireless link.
 7. The method recited in claim 1, wherein a wired link connects a main unit that includes the speech recognition engine to a speech unit that includes the microphone array, the adaptive filter, and the speech coder.
 8. The method recited in claim 1, further comprising adjusting the beam pattern to maximize gain associated with the input speech signal in the direction associated with the user speaking the natural language utterance.
 9. The method recited in claim 1, further comprising complementing the microphone array with a Voice over IP speech interface that allows the user to connect to and interact with a system that includes one or more of the microphone array, the adaptive filter, the speech coder, or the speech recognition engine from a remote location.
 10. The method recited in claim 1, wherein the microphone array includes multiple microphones arranged in a one-dimensional linear shape.
 11. The method recited in claim 10, further comprising adjusting the beam pattern to maximize gain associated with the input speech signal in the direction associated with the user speaking the natural language utterance.
 12. The method recited in claim 1, wherein the microphone array includes multiple microphones arranged in a two-dimensional circular, square, or triangular shape.
 13. The method recited in claim 1, wherein the microphone array includes multiple physically distributed microphones arranged to create a three-dimensional array.
 14. A system for filtering and eliminating noise from natural language speech utterances, comprising: a microphone array configured to add one or more nulls to a beam pattern steered to point in a direction associated with a user speaking a natural language utterance to capture an input speech signal corresponding to the natural language utterance, wherein the one or more nulls notch out point or limited area noise sources from the input speech signal; an adaptive filter coupled to the microphone array, wherein the adaptive filter is configured to: receive the input speech signal corresponding to the natural language utterance from the microphone array and compare environmental, noise to the input speech signal to set one or more parameters associated with the adaptive filter; use band shaping and notch filtering to remove narrow-band noise from the input speech signal received from the microphone array according to the one or more parameters; and suppress cross-talk and environmentally caused echoes in the input speech signal received from the microphone array using adaptive echo cancellation; a speech coder arranged between the adaptive filter and a speech recognition engine, wherein the speech coder is configured to receive the input speech signal passed through the adaptive filter and use adaptive lossy audio compression to remove momentary gaps from the input speech signal and variable rate sampling to compress and digitize the input speech signal, wherein the speech coder optimizes the adaptive lossy audio compression and the variable rate sampling to only preserve components in the input speech signal that will be input to the speech recognition engine; and a transceiver configured to communicate the digitized input speech signal from a buffer in the speech coder to the speech recognition engine at a rate that depends on available bandwidth associated with a communication link that connects the transceiver and the speech recognition engine.
 15. The system recited in claim 14, wherein the speech coder is configured to use the adaptive lossy audio compression to remove the momentary gaps from the input speech signal to prevent errors in the speech recognition engine.
 16. The system recited in claim 14, wherein the speech coder is configured to use the variable rate sampling to maximize a fidelity associated with the digitized input speech signal and minimize the available bandwidth that the transceiver uses to transmit the digitized input speech signal to the speech recognition engine.
 17. The system recited in claim 16, wherein the speech coder is further configured to adapt a rate associated with digitizing and compressing the input speech signal to minimize the available bandwidth that the transceiver uses to transmit the digitized input speech signal to the speech recognition engine.
 18. The system recited in claim 14, wherein the adaptive filter has a pass band set to optimize a signal to noise ratio associated with the components in the input speech signal that will be input to the speech recognition engine.
 19. The system recited in claim 14, further comprising: a main unit that includes the speech recognition engine; and a speech unit that includes the microphone array, the adaptive filter, and the speech coder, wherein the main unit and the speech unit are physically separate and communicate wirelessly over the communication link.
 20. The system recited in claim 14, further comprising: a main unit that includes the speech recognition engine; and a speech unit that includes the microphone array, the adaptive filter, and the speech coder, wherein the communication link includes one or more wires that connect the main unit and the speech unit.
 21. The system recited in claim 14, wherein the microphone array is further configured to adjust the beam pattern to maximize gain associated with the input speech signal in the direction associated with the user speaking the natural language utterance.
 22. The system recited in claim 14, further comprising a Voice over IP speech interface configured to complement the microphone array, and allow the user to connect to and interact with the system from a remote location.
 23. The system recited in claim 14, wherein the microphone array includes multiple microphones arranged in a one-dimensional linear shape.
 24. The system recited in claim 23, wherein the microphone array is further configured to adjust the beam pattern to maximize gain associated with the input speech signal in the direction associated with the user speaking the natural language utterance.
 25. The system recited in claim 14, wherein the microphone array includes multiple microphones arranged in a two-dimensional circular, square, or triangular shape.
 26. The system recited in claim 14, wherein the microphone array includes multiple physically distributed microphones arranged to create a three-dimensional array. 